GeneralPurposeAllocator: default to store more stack frames in test mode
GeneralPurposeAllocator: default to store more stack frames in test mode

Now tests will by default store 8 stack frames per allocation rather
than the normal default of 4.

raulgrell/zig,raulgrell/zig,andrewrk/zig,andrewrk/zig,raulgrell/zig,zig-lang/zig,raulgrell/zig,zig-lang/zig,zig-lang/zig,raulgrell/zig